Patent GB-298320-A (GB)
Title: Improvements in tubing catchers for oil wells and the like
IPC: E21B23/01
Filed: 1927-08-09
Abstract: 298,320. Dillon, S. V. Aug. 9, 1927. Borehode apparatus.-A tubing. catcher for use in oil wells &c., wherein the tubing may slide axially in the entire catcher, comprises a slip assembly with friction means engaging the well casing and a slidable wedge block resting on, and forcing down, the slip assembly in the casing as the tubing descends, the wedge block functioning when required to expand the slips into locking engagement with the casing. In Figs. 1 and 2, a heavy wedge sleeve 6 is slidable on the tubing 1 and has upper and lower annular recesses 9, 12, from which vertical grooves 11, 14, extend; collars 3. 4 on the tubing have ribs 7, 8 which, when out of alignment with the grooves 11, 14. allow, only very limited relative vertical movement between the wedge sleeve 6 and the tubing 1, but which may be turned into alignment with the grooves to permit a substantial increase of such relative movement. Below the wedge sleeve 6 is a sleeve 15 to which the stems 19 of serrated slips 21 are pivoted on pins 20; the stems 19 have enlarged ends to hold them in the sleeve 15 if the pins 20 break. The sleeve 15 carries leaf springs 16 in such frictional engagement with the well casing as to be capable of holding the sleeve 15 and slips. Springs 24 secured to the wedge sleeve 6 normally rest on ledges 27 on the sleeve 15; radially slidable pins 28, carried by the sleeve 15, are operated by cams 29, 30, on the tubing 1 to dislodge the springs 24 when desired. In use, the parts are lowered into the. well in the position shown in Fig. 1. If a break occurs above the wedge sleeve 6, the tubing falls through the sleeve 15, the cams 29 actuate the pins 28 to release the springs 24, and the wedge sleeve 6 then falls to spread the. slips 21 into engagement with the well casing! to hold the whole of the parts against further falling. If no break occurs and it is desired to lock the device in the casing, the tubing 1 is turned to cause cams 30 to effect release of the springs 24; the ribs 8 are simultaneously brought into alignment with the grooves 14, so that the wedge sleeve 6 may fall and spread the slips 21 as before. To release the device, the tubing 1 is lifted, the collar 4 then lifting the wedge sleeve 6, and fingers 32 on the latter ultimately lift the, slips 21 and sleeve 15; during this movement, if the ribs 8 are in engagement with the grooves 14, a collar 35 on the tubing acts through the pins 28 to prevent, the springs 24 seating on the ledges 27, but if the ribs are not in engagement, the springs 24 automatically engage the ledges. In a modification, Fig. 7, the sleeve 15<a> has upwardly directed springs 16<a> with outwardly turned upper ends engaging projections 16<c> on the wedge block 6<a> ; on fracture or falling of the tubing, the projections 16<c> expand the springs 16<a>, allowing the wedge block 6<a> to operate the slips 21<a>, Radial pins 28 and cams 29, 30, as in Fig. 1, may also be provided in this form. In a further form, Fig. 9, the sleeve 15<b> is arranged above the, wedge block 6f and the springs 16f, which engage the well casing, also bear against the stems 19f of slips 21f, while the latter normally engage a shoulder 6<G> on the wedge block to support the latter; radially movable pins 28f, operated by cams 29f or 30f, free the. wedge block when required.